Mplayer, FFmpeg Gain VA-API Support

Video acceleration APIs for Linux has been a hot topic recently
with NVIDIA having introduced VDPAU
last month (the Video Decode and Presentation API for Unix) that brings PureVideo-like
features to Linux with great
results while it's already finding its way into MPlayer, FFmpeg, MythTV,
Xine,
and VLC.
AMD has been working hard on XvBA
(X-Video Bitstream Acceleration),
but that has yet to be officially introduced. In the open-source realm there has
been talk of extending
XvMC to support video formats besides MPEG-2, but that hasn't yet amounted
to anything. Today though another video API is now on scene with VA-API
finally being implemented in MPlayer and FFmpeg.

VA-API (short for Video Acceleration API) is a software API that
has the backing of Intel and is designed to accelerate video decoding, sub-picture
blending, and rendering on the graphics processor. The hopes with VA-API are to
ultimately replace X-Video Motion Compensation as being the predominate video
API for Linux systems. Unlike XvMC that is limited to MPEG-2 and IDCT / Motion
Compensation, VA-API is designed to support other standards such as MPEG-4 and
VC-1 along with accelerating IDCT, Motion Compensation, VLC, bitstream processing,
spatial-temporal deinterlacing, inverse quantization, and other functions.

The Video Acceleration API has gone through several revisions
this year and last year, but it has yet to see any wide adoption. The libVa library
provides the VA-API implementation and is put out under an open-source MIT license
while the only driver implementing VA-API support is the Poulsbo video driver.
The Intel Poulsbo graphics driver is closed-source while their DRM kernel driver
is open-source. Poulsbo is the code-name for Intel's MID (Mobile Internet Device)
chipset that is used in conjunction with the Silverthorne Atom processors. However,
the Poulsbo chipset is used on very few netbooks and the MIDs with these chipsets
are not very common (at least not in the US). One system that does use this chipset
is the Dell Inspiron Mini 12.

If you happen to have hardware with the Intel Poulsbo and Intel's
closed-source driver, patches for adding VA-API support to MPlayer
and FFmpeg
have just been published. The Ubuntu
Mobile team and Intel's
Moblin project have been working to add VA-API support within the Helix media
player stack, but now it's here for the widely popular MPlayer.

The VA-API patches aren't coming out of Intel, but instead out
of Splitted-Desktop Systems, which is a company specializing in Internet media
stations, VoIP, HDTV, and other products. These patches allow for VA-API support
within MPlayer and FFmpeg for MPEG-2, MPEG-4 ASP (DivX), and MPEG-4 AVC (H.264)
codecs. Some of the caveats though in this initial support include non-accelerated
decoding is not supported with the VA-API renderer, the MPlayer OSD (On-Screen
Display) isn't supported, VC-1 streams aren't yet implemented, and there is a
H.264 issue that may cause some visual defects when watching streams with VA-API.

If you want to check out these MPlayer and FFmpeg patches for
VA-API until they enter the mainline code-base for these two projects, they can
be found at Splitted-Desktop.com.
The patch that implements this support is about 3,500 lines of code.

This is good news for those with Intel Poulsbo MIDs, but that
is a very small audience right now. Poulsbo should begin appearing in more systems
next year, but hopefully next year we will also see the Video Acceleration API
find its way into other X.Org graphics drivers or all GPU vendors and drivers settle on one API for Linux.

Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via Twitter and Google+ or contacted via MichaelLarabel.com.